Combination percussion and rotary drill



June 21, 1932. J, A MaCDONELL COMBINATION 'PERCUSSION AND ROTARY DRILL Filed May 9, 1931 Patented `lune 21, 1932 UNITED STATI-:s

JAMES A. MAcDoNEL.; or Illini. ir'

COMBINATION rERcUssIoNAND ROTARY DIL;

Application led May 9,

This invention relates to drilling tools and particularly to those of the character commonly used for the drilling of deep wells.

In the drilling of such wells it has been ZS common to use what is known as percussion drills and also what is known as rotary drills, each having certain advantages over the other in connection with certain classes of work, but these so far as I am aware, have l always been used separately.

The object of my invention is to provide a drill head of the character described, which will include bits of both of said types adapted to operate conjointly and thereby combine the separate advantages thereof and enabling work to be more rapidly performed than is possible by the use of either type alone.

The invention is fully described in the following specification, and while in its broader aspect it is capable of embodiment in numerous forms, one embodiment thereof is illustrated in the accompanying drawing, in which- Figure 1 is a side elevation of a drill head embodying the invention, with its lower end submerged in a well being drilled and with the bit members in normal relation. Fig. 2 is a central vertical section thereof on the line 2-2 in Fig. 1, with parts in full. Figs.

3 and 4 are cross-sections, respectively, on the lines 3 3 and 4--4 in Fig. 1. Fig. 5 is a view similar to Fig. 1, with the upper portion of the drill head broken away and having a modified form of rotary cutting member, and Fig. 6 is a section on the line 6-6 in Fig. 5, with a part in full.

Referring to the drawing, 1 .designates the stem or shank of the drill head, which is adapted to be attached at its upper end to the lower end of a drill pipe for rotary and reciprocatory movements therewith.

A bit 2 of the type commonly used'v for percussion drilling and which, in the present instance, is shown as being of broad blade type, is removably attached to the lower end lof the stem 1, and preferably has a channel 3 therethrough in communication with a channel 4 extending through the stem 1 and through which water may be introduced into the bottoniv ofthe well during a-drilling operation, aswell understood in thev art. A .A A" col ar 5 is mounted for reciprocatoryi movements on the steml and is causedl to have rotary movements therewith reason ,ofa 5'5 feathered or other suitable connection' olf the two. l. A coiled expansion spring 6 encircles stem `l,Ibetween the coll-ar 5 and a fixed collar` 7 on thestefn to exert ayielding downward 6U pressure(onY tl'ie collar, and ,thedownwardi stroke of the collar is limited by the feathers on the collar strikiiigthelowerend of the v Y grooves 8, inwhich they work, or in any other', suitable manner. i y l v I A; rotary ofbit 9 is detachably threaded or otherwise suitably se'curedtthe colflan. This" bit lias'its'lklowr end forkedC to stralddle the' percussion bit 2` and to provide" fluuttingY bladeV 10' at. .ach: side of: the bit 2. The out; 70 tingA end of therotaryl bitf 9V isnrm'aliy disf'- pos'ed'belw vtlie'eiidy of tlieperbussion bit 2 to adapt the latter during a rotary cutting movement of the former to be axially reciprox cated to have percussion drilling movement.

In the form of the invention shown in Figs. 5 and 6, the rotary bit comprises a forked member 12, which is mounted at its upper end for reciprocatory movements on the stem 1, and for rotary movements there- B' f with, and has the lower ends of its fork arms provided with transversely projecting studs 13 carrying cutting disks 14, which during a rotation of the drill head cause a rotary cutting of the bottom surface of the well being drilled, as is apparent.

In the use of myv improved tool, the drill head, for the purpose of using the percussion K bit in the drilling operation, is reciprocated in the usual manner to cause such bit to have repeated striking engagement with the bottom of the well, and at the same time the drill head is rotated so as to cause the rotarybit member to have rotary drilling coaction with the well bottom, the same as is common in the use of tools of the rotary type. It is apparent that by this combined percussion and rotary drilling actions, a well is more quickly drilled than when either apercussion or rotary type .l of drill is used alone. 10

I wish it understood that my invention is not limited to any specific construction, arrangement or form of the parts, as itis capable of numerous modifications and changes without departing from the spirit of the claims. I also wish it understood that in carrying out my invention, rotary and percussion bits of the type commonlyv employed, may be used.

Having thus described my invention, what I claim as new and desire to secure by United States Letters Patent is:

1. In a drin head of the glimmer .de--V scribed, a stem, a percussion bit carried by the stem and a rotary bit carried for rotary movements with the stem, and for reciprocatory movements relative thereto and normally standing projected relative to the percussion bit.

2. A drill head of Vthe class described, including astem, a percussion bit attached to the lower end of the stem, a rotary bit of forked form straddling the percussionbit and mounted on the stem for rotary movements therewith, and axial reciprocatory movements relative thereto, and means yieldingly acting on the rotary bit to normally maintain its cutting end projected beyond that of the percussion bit. v Y

3. The combination with a drill stem, of a percussion type bit rigidly secured thereto, a rotary typebit splined to said stem, and resilient means for maintaining said rotary type bit projected while said steml is reciprocated.

In testimony whereof I have' hereunto signed my name to this specification.

JAMES A. MACDONELL. Y 

